Is there such a thing as too much power? Everyone knows the problems with underpowering a cab, but can you overpower one too?

For example, say 1000 wats into a 350 watt cabinet...
(Think a Crest CA9 bridged into an Epifani UL112)

How do you keep from blowing the speaker? How much power is needed to have good transients that jump out when you need them to?

How much IS too much?

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Crest CA9 bridged is about 2000 watts into 4 ohms. It isn't so much the number of watts, it's what you do with them. Sure, you can run 2000 watts into a 350 watt cab, but you need to use common sense and listen to what your cab is doing. If it starts running into trouble, believe me, it'll let you know.

Say if i was pushing a 300 watt head into a 700 watt cab, id have to drive the head hard to get those cones moving thus the head will clip. If you've got something very powerful on the other hand, you won't have to turn the volume up much to get a loud sound with out stressing the head.

I think the rule of thumb that many of the high power guys agree on (oh boy am I out on a limb!) add up the power handling of your cabs, double that number and that should be the OPTIMUM wattage.

an experienced player can utilize almost any wattage from 50w into a 12" up to several kilowatts into a 12" or 10', pick your speaker size.

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Okay, let's say you have a 2x10" cabinet that is rated for 400W, and you follow this 2X recommendation and use an 800W amp. So, you decide, "I'm going to play my 7-string bass tuned to low F# and pound on that low F# string".

What do you think is going to happen?

After buying some new woofers, perhaps you will think again.....

There are many variables at work here, all of which make a "rule of thumb" a gross over-simplification.

One point worth noting is that ported cabinets do not handle their full rated power below the cabinet's tuning frequency. A 400W rated ported cabinet tuned to 50Hz will not handle 400W at 20 Hz, 30 Hz, or 40 Hz, let alone 800W.

Headroom is great. However, excess power can damage a speaker, especially at low frequencies. As always, moderation is key. Listen for speaker distress and back off when necessary.

One point worth noting is that ported cabinets do not handle their full rated power below the cabinet's tuning frequency. A 400W rated ported cabinet tuned to 50Hz will not handle 400W at 20 Hz, 30 Hz, or 40 Hz, let alone 800W.

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The don't handle their full power above fs either, at least not cleanly. It's not unusual for a driver to be xmax limited at no more than 20% of rated power in the first half-octave above the tuning frequency.

The main problem with that rig is that it might not have the headroom to compete with really loud guitars and drums. But the worst that should happen if you crank it way up is that it'll sound like poo.

Upon reading the specs on a Selenium speaker a while back, I had my eyes opened to the fact that they recommend running their speakers with an amp that produces twice the RMS rating of the speaker, for headroom purposes, to stay away from the dreaded clipping.

Okay, let's say you have a 2x10" cabinet that is rated for 400W, and you follow this 2X recommendation and use an 800W amp. So, you decide, "I'm going to play my 7-string bass tuned to low F# and pound on that low F# string".

The don't handle their full power above fs either, at least not cleanly. It's not unusual for a driver to be xmax limited at no more than 20% of rated power in the first half-octave above the tuning frequency.

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Thanks for this information.

Seems to me facts like this are often overlooked in simplistic "take the cabinet's rms rating and double the amp power" rule-of-thumb suggestions.

If the average ported cabinet cannot take more than 20% of its rated power in the low end fundamentals, what is happening when users put double the rated power into the cabinet?